State Highway Safety Showcase

In April, 2012, the Michigan Office of Highway Safety Planning (OHSP) initiated a project with Western Michigan University to research and recommend a scientifically valid performance standard for Michigan’s federally-funded overtime traffic enforcement grants.

Many variables were considered, including grant budgets, officer strength, dual officer cars, day and time of the week worked, weather, jurisdiction, agency size, driver population, and agency grant-funded enforcement activity reported over the last five years.

Law enforcement focus groups, web surveys, and key demographic information such as vehicle registrations, vehicle miles of travel (VMT), county populations, and agency size were all incorporated into the analysis to provide a statistically valid comparison of agencies, regardless of their location or size.

After a year of data collection and analysis, the performance metric for NHTSA-funded enforcement grants was developed and is called “equivalent stops per billed hours.” This metric can be expressed as the following:

Equivalent stops = 4 x the number of number of arrests + total number of vehicle stops ÷ by total billed hours

One of the benefits the new metric has is that it not only credits each agency for every stop they make, but it also assigns a higher value to arrests made on grant-funded enforcement stops. Based on focus group and agency reported data, the average arrest is calculated as four times the amount of a traffic stop in this metric. The number of arrests were calculated by adding the reported number of suspended licenses (DWLS), reckless driving, operating while intoxicated (OWI), high BAC (0.17 or higher), drugs, fugitives, weapons, recovered stolen vehicles, other felony arrests, and other misdemeanor arrests.

The new metric provides more accurate and realistic performance values for safety belt and impaired driving enforcement. Based on previous grant-funded agency reported data and the equivalent stops per total billed hour metric, the calculated values of the standard are based on the performance level of 85 percent (percentile) of the agencies that reported enforcement activity to achieve the standard. A goal of the 50th percentile value will also be included, and agencies will be encouraged to achieve that level of performance for recognition of outstanding performance.

The Michigan OHSP will also provide a ranking to identify high performing agencies, using the recommended performance standard, which will be shared after every enforcement period. Agencies showing a deficient level of performance will be notified that future funding is contingent upon satisfactory performance by meeting the stated minimum standard. Agencies will lose grant funding if they are unable to meet the standard after several mobilization periods.

OHSP will be requiring grant-funded agencies to achieve at least 1.09 equivalent stops for Click it or Ticket overtime. For impaired driving enforcement, the state was split into two geographic regions. Agencies in the state’s Upper Peninsula will be required to conduct at least .72 equivalent stops, and agencies in the Lower Peninsula will be required to conduct at least 1.29 equivalent stops in FY14.